Take a small glass, water down some vinegar to as strong as you can stand it. Gargle a few mouthfuls then drink a sip of it at the end. It's strong, but you'll get used to it, unless you don't. The theory I heard is that the acid in the vinegar will kill bacteria and loosens phlegm. Sounds plausible. If that's true, you could use white or balsamic vinegar, but it may not be as palatable. If the taste is too strong for you, try a honey chaser. A spoonful of honey also makes for a good sore throat remedy. At least as helpful as most cough drops.
I gargle with this every morning through the fall and winter and it has helped me. I have not done a double-blind randomized clinical study on it, to quantify my findings. However, when I get up in the morning with a nagging cough, a dose of this breaks up the phlegm in no time.
I have never tried the unfiltered apple cider vinegar with "the mother" in it, so I don't know if that's better or not.
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